NAT: total users and sessions gauges (VPP-1484)

Change-Id: I41a82e21571d5c64d01af72cd88c3983afac26ed
Signed-off-by: Matus Fabian <matfabia@cisco.com>

diff --git a/src/plugins/nat/dslite.c b/src/plugins/nat/dslite.c
index 12c8132..883acec 100644 (file)
--- a/src/plugins/nat/dslite.c
+++ b/src/plugins/nat/dslite.c
@@ -67,6 +67,16 @@ dslite_init (vlib_main_t * vm)
 
   dm->is_ce = 0;
 
+  /* Init counters */
+  dm->total_b4s.name = "total-b4s";
+  dm->total_b4s.stat_segment_name = "/dslite/total-b4s";
+  vlib_validate_simple_counter (&dm->total_b4s, 0);
+  vlib_zero_simple_counter (&dm->total_b4s, 0);
+  dm->total_sessions.name = "total-sessions";
+  dm->total_sessions.stat_segment_name = "/dslite/total-sessions";
+  vlib_validate_simple_counter (&dm->total_sessions, 0);
+  vlib_zero_simple_counter (&dm->total_sessions, 0);
+
   dslite_dpo_module_init ();
 }
 

diff --git a/src/plugins/nat/dslite.h b/src/plugins/nat/dslite.h
index 73902e3..066bfcf 100644 (file)
--- a/src/plugins/nat/dslite.h
+++ b/src/plugins/nat/dslite.h
@@ -87,6 +87,10 @@ typedef struct
   u32 first_worker_index;
   u16 port_per_thread;
 
+  /* counters/gauges */
+  vlib_simple_counter_main_t total_b4s;
+  vlib_simple_counter_main_t total_sessions;
+
   /* If set then the DSLite component behaves as CPE/B4
    * otherwise it behaves as AFTR */
   u8 is_ce;

diff --git a/src/plugins/nat/dslite_in2out.c b/src/plugins/nat/dslite_in2out.c
index 5c1de19..cbb5d98 100644 (file)
--- a/src/plugins/nat/dslite_in2out.c
+++ b/src/plugins/nat/dslite_in2out.c
@@ -71,6 +71,10 @@ slow_path (dslite_main_t * dm, dslite_session_key_t * in2out_key,
       b4_index = b4_kv.value = b4 - dm->per_thread_data[thread_index].b4s;
       clib_bihash_add_del_16_8 (&dm->per_thread_data[thread_index].b4_hash,
                                &b4_kv, 1);
+
+      vlib_set_simple_counter (&dm->total_b4s, thread_index, 0,
+                              pool_elts (dm->
+                                         per_thread_data[thread_index].b4s));
     }
   else
     {
@@ -139,6 +143,10 @@ slow_path (dslite_main_t * dm, dslite_session_key_t * in2out_key,
       clib_dlist_addtail (dm->per_thread_data[thread_index].list_pool,
                          s->per_b4_list_head_index,
                          elt - dm->per_thread_data[thread_index].list_pool);
+
+      vlib_set_simple_counter (&dm->total_sessions, thread_index, 0,
+                              pool_elts (dm->per_thread_data
+                                         [thread_index].sessions));
     }
 
   s->in2out = *in2out_key;

diff --git a/src/plugins/nat/nat.c b/src/plugins/nat/nat.c
index 2e1aa77..c2c812d 100755 (executable)
--- a/src/plugins/nat/nat.c
+++ b/src/plugins/nat/nat.c
@@ -322,6 +322,9 @@ nat_user_get_or_create (snat_main_t * sm, ip4_address_t * addr, u32 fib_index,
       /* add user */
       if (clib_bihash_add_del_8_8 (&tsm->user_hash, &kv, 1))
        nat_log_warn ("user_hash keay add failed");
+
+      vlib_set_simple_counter (&sm->total_users, thread_index, 0,
+                              pool_elts (tsm->users));
     }
   else
     {
@@ -397,6 +400,8 @@ nat_session_alloc_or_recycle (snat_main_t * sm, snat_user_t * u,
                          per_user_translation_list_elt - tsm->list_pool);
 
       s->user_index = u - tsm->users;
+      vlib_set_simple_counter (&sm->total_sessions, thread_index, 0,
+                              pool_elts (tsm->sessions));
     }
 
   return s;
@@ -471,6 +476,9 @@ nat_ed_session_alloc (snat_main_t * sm, snat_user_t * u, u32 thread_index,
                              s->per_user_list_head_index,
                              per_user_translation_list_elt - tsm->list_pool);
        }
+
+      vlib_set_simple_counter (&sm->total_sessions, thread_index, 0,
+                              pool_elts (tsm->sessions));
     }
 
   return s;
@@ -2207,6 +2215,16 @@ snat_init (vlib_main_t * vm)
 
   nat_dpo_module_init ();
 
+  /* Init counters */
+  sm->total_users.name = "total-users";
+  sm->total_users.stat_segment_name = "/nat44/total-users";
+  vlib_validate_simple_counter (&sm->total_users, 0);
+  vlib_zero_simple_counter (&sm->total_users, 0);
+  sm->total_sessions.name = "total-sessions";
+  sm->total_sessions.stat_segment_name = "/nat44/total-sessions";
+  vlib_validate_simple_counter (&sm->total_sessions, 0);
+  vlib_zero_simple_counter (&sm->total_sessions, 0);
+
   /* Init IPFIX logging */
   snat_ipfix_logging_init (vm);
 

diff --git a/src/plugins/nat/nat.h b/src/plugins/nat/nat.h
index e851e2f..06d0dec 100644 (file)
--- a/src/plugins/nat/nat.h
+++ b/src/plugins/nat/nat.h
@@ -532,6 +532,10 @@ typedef struct snat_main_s
   u16 mss_clamping;
   u16 mss_value_net;
 
+  /* counters/gauges */
+  vlib_simple_counter_main_t total_users;
+  vlib_simple_counter_main_t total_sessions;
+
   /* API message ID base */
   u16 msg_id_base;
 

diff --git a/src/plugins/nat/nat64.c b/src/plugins/nat/nat64.c
index 8bcca2b..4dbfb05 100644 (file)
--- a/src/plugins/nat/nat64.c
+++ b/src/plugins/nat/nat64.c
@@ -240,6 +240,16 @@ nat64_init (vlib_main_t * vm)
   vec_add1 (im->add_del_interface_address_callbacks, cb4);
   nm->ip4_main = im;
 
+  /* Init counters */
+  nm->total_bibs.name = "total-bibs";
+  nm->total_bibs.stat_segment_name = "/nat64/total-bibs";
+  vlib_validate_simple_counter (&nm->total_bibs, 0);
+  vlib_zero_simple_counter (&nm->total_bibs, 0);
+  nm->total_sessions.name = "total-sessions";
+  nm->total_sessions.stat_segment_name = "/nat64/total-sessions";
+  vlib_validate_simple_counter (&nm->total_sessions, 0);
+  vlib_zero_simple_counter (&nm->total_sessions, 0);
+
   return 0;
 }
 
@@ -319,7 +329,13 @@ nat64_add_del_pool_addr (ip4_address_t * addr, u32 vrf_id, u8 is_add)
       /* Delete sessions using address */
         /* *INDENT-OFF* */
         vec_foreach (db, nm->db)
-          nat64_db_free_out_addr (db, &a->addr);
+          {
+            nat64_db_free_out_addr (db, &a->addr);
+            vlib_set_simple_counter (&nm->total_bibs, db - nm->db, 0,
+                                     db->bib.bib_entries_num);
+            vlib_set_simple_counter (&nm->total_sessions, db - nm->db, 0,
+                                     db->st.st_entries_num);
+          }
 #define _(N, id, n, s) \
       clib_bitmap_free (a->busy_##n##_port_bitmap);
       foreach_snat_protocol
@@ -584,12 +600,16 @@ nat64_static_bib_worker_fn (vlib_main_t * vm, vlib_node_runtime_t * rt,
       continue;
 
     if (static_bib->is_add)
-      (void) nat64_db_bib_entry_create (db, &static_bib->in_addr,
-                                        &static_bib->out_addr,
-                                        static_bib->in_port,
-                                        static_bib->out_port,
-                                       static_bib->fib_index,
-                                        static_bib->proto, 1);
+      {
+          (void) nat64_db_bib_entry_create (db, &static_bib->in_addr,
+                                            &static_bib->out_addr,
+                                            static_bib->in_port,
+                                            static_bib->out_port,
+                                            static_bib->fib_index,
+                                            static_bib->proto, 1);
+          vlib_set_simple_counter (&nm->total_bibs, thread_index, 0,
+                                   db->bib.bib_entries_num);
+      }
     else
       {
         addr.as_u64[0] = static_bib->in_addr.as_u64[0];
@@ -598,7 +618,13 @@ nat64_static_bib_worker_fn (vlib_main_t * vm, vlib_node_runtime_t * rt,
                                         static_bib->proto,
                                         static_bib->fib_index, 1);
         if (bibe)
-          nat64_db_bib_entry_free (db, bibe);
+          {
+            nat64_db_bib_entry_free (db, bibe);
+            vlib_set_simple_counter (&nm->total_bibs, thread_index, 0,
+                                     db->bib.bib_entries_num);
+            vlib_set_simple_counter (&nm->total_sessions, thread_index, 0,
+                                     db->st.st_entries_num);
+          }
       }
 
       static_bib->done = 1;
@@ -703,6 +729,9 @@ nat64_add_del_static_bib_entry (ip6_address_t * in_addr,
                                       fib_index, proto, 1);
          if (!bibe)
            return VNET_API_ERROR_UNSPECIFIED;
+
+         vlib_set_simple_counter (&nm->total_bibs, thread_index, 0,
+                                  db->bib.bib_entries_num);
        }
     }
   else
@@ -711,7 +740,11 @@ nat64_add_del_static_bib_entry (ip6_address_t * in_addr,
        return VNET_API_ERROR_NO_SUCH_ENTRY;
 
       if (!nm->sm->num_workers)
-       nat64_db_bib_entry_free (db, bibe);
+       {
+         nat64_db_bib_entry_free (db, bibe);
+         vlib_set_simple_counter (&nm->total_bibs, thread_index, 0,
+                                  db->bib.bib_entries_num);
+       }
     }
 
   if (nm->sm->num_workers)
@@ -1143,6 +1176,10 @@ nat64_expire_worker_walk_fn (vlib_main_t * vm, vlib_node_runtime_t * rt,
   u32 now = (u32) vlib_time_now (vm);
 
   nad64_db_st_free_expired (db, now);
+  vlib_set_simple_counter (&nm->total_bibs, thread_index, 0,
+                          db->bib.bib_entries_num);
+  vlib_set_simple_counter (&nm->total_sessions, thread_index, 0,
+                          db->st.st_entries_num);
 
   return 0;
 }

diff --git a/src/plugins/nat/nat64.h b/src/plugins/nat/nat64.h
index d365e12..0a60571 100644 (file)
--- a/src/plugins/nat/nat64.h
+++ b/src/plugins/nat/nat64.h
@@ -108,6 +108,10 @@ typedef struct
   /* The process node which orcherstrates the cleanup */
   u32 nat64_expire_walk_node_index;
 
+  /* counters/gauges */
+  vlib_simple_counter_main_t total_bibs;
+  vlib_simple_counter_main_t total_sessions;
+
   ip4_main_t *ip4_main;
   snat_main_t *sm;
 } nat64_main_t;

diff --git a/src/plugins/nat/nat64_in2out.c b/src/plugins/nat/nat64_in2out.c
index 372931c..660df09 100644 (file)
--- a/src/plugins/nat/nat64_in2out.c
+++ b/src/plugins/nat/nat64_in2out.c
@@ -221,6 +221,9 @@ nat64_in2out_tcp_udp_set_cb (ip6_header_t * ip6, ip4_header_t * ip4,
                                       sport, out_port, fib_index, proto, 0);
          if (!bibe)
            return -1;
+
+         vlib_set_simple_counter (&nm->total_bibs, ctx->thread_index, 0,
+                                  db->bib.bib_entries_num);
        }
 
       nat64_extract_ip4 (&ip6->dst_address, &daddr.ip4, fib_index);
@@ -229,6 +232,9 @@ nat64_in2out_tcp_udp_set_cb (ip6_header_t * ip6, ip4_header_t * ip4,
                                  &daddr.ip4, dport);
       if (!ste)
        return -1;
+
+      vlib_set_simple_counter (&nm->total_sessions, ctx->thread_index, 0,
+                              db->st.st_entries_num);
     }
 
   ip4->src_address.as_u32 = bibe->out_addr.as_u32;
@@ -312,6 +318,9 @@ nat64_in2out_icmp_set_cb (ip6_header_t * ip6, ip4_header_t * ip4, void *arg)
                                           fib_index, IP_PROTOCOL_ICMP, 0);
              if (!bibe)
                return -1;
+
+             vlib_set_simple_counter (&nm->total_bibs, ctx->thread_index, 0,
+                                      db->bib.bib_entries_num);
            }
 
          nat64_extract_ip4 (&ip6->dst_address, &daddr.ip4, fib_index);
@@ -320,6 +329,9 @@ nat64_in2out_icmp_set_cb (ip6_header_t * ip6, ip4_header_t * ip4, void *arg)
                                      &daddr.ip4, 0);
          if (!ste)
            return -1;
+
+         vlib_set_simple_counter (&nm->total_sessions, ctx->thread_index, 0,
+                                  db->st.st_entries_num);
        }
 
       nat64_session_reset_timeout (ste, ctx->vm);
@@ -549,6 +561,9 @@ nat64_in2out_unk_proto_set_cb (ip6_header_t * ip6, ip4_header_t * ip4,
                                       0);
          if (!bibe)
            return -1;
+
+         vlib_set_simple_counter (&nm->total_bibs, s_ctx->thread_index, 0,
+                                  db->bib.bib_entries_num);
        }
 
       nat64_extract_ip4 (&ip6->dst_address, &daddr.ip4, fib_index);
@@ -556,6 +571,9 @@ nat64_in2out_unk_proto_set_cb (ip6_header_t * ip6, ip4_header_t * ip4,
        nat64_db_st_entry_create (db, bibe, &ip6->dst_address, &daddr.ip4, 0);
       if (!ste)
        return -1;
+
+      vlib_set_simple_counter (&nm->total_sessions, s_ctx->thread_index, 0,
+                              db->st.st_entries_num);
     }
 
   nat64_session_reset_timeout (ste, s_ctx->vm);
@@ -635,6 +653,9 @@ nat64_in2out_tcp_udp_hairpinning (vlib_main_t * vm, vlib_buffer_t * b,
                                       sport, out_port, fib_index, proto, 0);
          if (!bibe)
            return -1;
+
+         vlib_set_simple_counter (&nm->total_bibs, thread_index, 0,
+                                  db->bib.bib_entries_num);
        }
 
       nat64_extract_ip4 (&ip6->dst_address, &daddr.ip4, fib_index);
@@ -643,6 +664,9 @@ nat64_in2out_tcp_udp_hairpinning (vlib_main_t * vm, vlib_buffer_t * b,
                                  &daddr.ip4, dport);
       if (!ste)
        return -1;
+
+      vlib_set_simple_counter (&nm->total_sessions, thread_index, 0,
+                              db->st.st_entries_num);
     }
 
   if (proto == IP_PROTOCOL_TCP)
@@ -890,6 +914,9 @@ nat64_in2out_unk_proto_hairpinning (vlib_main_t * vm, vlib_buffer_t * b,
                                       0);
          if (!bibe)
            return -1;
+
+         vlib_set_simple_counter (&nm->total_bibs, thread_index, 0,
+                                  db->bib.bib_entries_num);
        }
 
       nat64_extract_ip4 (&ip6->dst_address, &daddr.ip4, fib_index);
@@ -897,6 +924,9 @@ nat64_in2out_unk_proto_hairpinning (vlib_main_t * vm, vlib_buffer_t * b,
        nat64_db_st_entry_create (db, bibe, &ip6->dst_address, &daddr.ip4, 0);
       if (!ste)
        return -1;
+
+      vlib_set_simple_counter (&nm->total_sessions, thread_index, 0,
+                              db->st.st_entries_num);
     }
 
   nat64_session_reset_timeout (ste, vm);
@@ -1510,6 +1540,8 @@ nat64_in2out_reass_node_fn (vlib_main_t * vm,
                            node->errors[NAT64_IN2OUT_ERROR_NO_TRANSLATION];
                          goto trace0;
                        }
+                     vlib_set_simple_counter (&nm->total_bibs, thread_index,
+                                              0, db->bib.bib_entries_num);
                    }
                  nat64_extract_ip4 (&ip60->dst_address, &daddr0.ip4,
                                     fib_index0);
@@ -1524,6 +1556,9 @@ nat64_in2out_reass_node_fn (vlib_main_t * vm,
                        node->errors[NAT64_IN2OUT_ERROR_NO_TRANSLATION];
                      goto trace0;
                    }
+
+                 vlib_set_simple_counter (&nm->total_sessions, thread_index,
+                                          0, db->st.st_entries_num);
                }
              reass0->sess_index = nat64_db_st_entry_get_index (db, ste0);
 

diff --git a/src/plugins/nat/nat64_out2in.c b/src/plugins/nat/nat64_out2in.c
index ba35de1..437052f 100644 (file)
--- a/src/plugins/nat/nat64_out2in.c
+++ b/src/plugins/nat/nat64_out2in.c
@@ -165,6 +165,12 @@ nat64_out2in_tcp_udp_set_cb (ip4_header_t * ip4, ip6_header_t * ip6,
       nat64_compose_ip6 (&ip6_saddr, &ip4->src_address, bibe->fib_index);
       ste =
        nat64_db_st_entry_create (db, bibe, &ip6_saddr, &saddr.ip4, sport);
+
+      if (!ste)
+       return -1;
+
+      vlib_set_simple_counter (&nm->total_sessions, ctx->thread_index, 0,
+                              db->st.st_entries_num);
     }
 
   ip6->src_address.as_u64[0] = ste->in_r_addr.as_u64[0];
@@ -240,6 +246,12 @@ nat64_out2in_icmp_set_cb (ip4_header_t * ip4, ip6_header_t * ip6, void *arg)
          nat64_compose_ip6 (&ip6_saddr, &ip4->src_address, bibe->fib_index);
          ste =
            nat64_db_st_entry_create (db, bibe, &ip6_saddr, &saddr.ip4, 0);
+
+         if (!ste)
+           return -1;
+
+         vlib_set_simple_counter (&nm->total_sessions, ctx->thread_index, 0,
+                                  db->st.st_entries_num);
        }
 
       nat64_session_reset_timeout (ste, ctx->vm);
@@ -397,6 +409,12 @@ nat64_out2in_unk_proto_set_cb (ip4_header_t * ip4, ip6_header_t * ip6,
 
       nat64_compose_ip6 (&ip6_saddr, &ip4->src_address, bibe->fib_index);
       ste = nat64_db_st_entry_create (db, bibe, &ip6_saddr, &saddr.ip4, 0);
+
+      if (!ste)
+       return -1;
+
+      vlib_set_simple_counter (&nm->total_sessions, ctx->thread_index, 0,
+                              db->st.st_entries_num);
     }
 
   nat64_session_reset_timeout (ste, ctx->vm);
@@ -802,6 +820,9 @@ nat64_out2in_reass_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
                        node->errors[NAT64_OUT2IN_ERROR_NO_TRANSLATION];
                      goto trace0;
                    }
+
+                 vlib_set_simple_counter (&nm->total_sessions, thread_index,
+                                          0, db->st.st_entries_num);
                }
              reass0->sess_index = nat64_db_st_entry_get_index (db, ste0);
              reass0->thread_index = thread_index;

diff --git a/src/plugins/nat/nat_inlines.h b/src/plugins/nat/nat_inlines.h
index 38cfc37..db5063c 100644 (file)
--- a/src/plugins/nat/nat_inlines.h
+++ b/src/plugins/nat/nat_inlines.h
@@ -159,6 +159,8 @@ nat44_delete_user_with_no_session (snat_main_t * sm, snat_user_t * u,
       pool_put_index (tsm->list_pool, u->sessions_per_user_list_head_index);
       pool_put (tsm->users, u);
       clib_bihash_add_del_8_8 (&tsm->user_hash, &kv, 0);
+      vlib_set_simple_counter (&sm->total_users, thread_index, 0,
+                              pool_elts (tsm->users));
     }
 }
 
@@ -177,6 +179,8 @@ nat44_delete_session (snat_main_t * sm, snat_session_t * ses,
   clib_dlist_remove (tsm->list_pool, ses->per_user_index);
   pool_put_index (tsm->list_pool, ses->per_user_index);
   pool_put (tsm->sessions, ses);
+  vlib_set_simple_counter (&sm->total_sessions, thread_index, 0,
+                          pool_elts (tsm->sessions));
 
   u_key.addr = ses->in2out.addr;
   u_key.fib_index = ses->in2out.fib_index;

diff --git a/test/test_nat.py b/test/test_nat.py
index 81aae4b..e3aa267 100644 (file)
--- a/test/test_nat.py
+++ b/test/test_nat.py
@@ -1015,6 +1015,10 @@ class MethodHolder(VppTestCase):
         """ Verify that there is no NAT44 user """
         users = self.vapi.nat44_user_dump()
         self.assertEqual(len(users), 0)
+        users = self.statistics.get_counter('/nat44/total-users')
+        self.assertEqual(users[0][0], 0)
+        sessions = self.statistics.get_counter('/nat44/total-sessions')
+        self.assertEqual(sessions[0][0], 0)
 
     def verify_ipfix_max_entries_per_user(self, data, limit, src_addr):
         """
@@ -1566,6 +1570,11 @@ class TestNAT44(MethodHolder):
             '/err/nat44-out2in/good out2in packets processed')
         self.assertEqual(err - totaln, 3)
 
+        users = self.statistics.get_counter('/nat44/total-users')
+        self.assertEqual(users[0][0], 1)
+        sessions = self.statistics.get_counter('/nat44/total-sessions')
+        self.assertEqual(sessions[0][0], 3)
+
     def test_dynamic_icmp_errors_in2out_ttl_1(self):
         """ NAT44 handling of client packets with TTL=1 """
 
@@ -4105,6 +4114,11 @@ class TestNAT44EndpointDependent(MethodHolder):
             '/err/nat44-ed-out2in/good out2in packets processed')
         self.assertEqual(err - totaln, 2)
 
+        users = self.statistics.get_counter('/nat44/total-users')
+        self.assertEqual(users[0][0], 1)
+        sessions = self.statistics.get_counter('/nat44/total-sessions')
+        self.assertEqual(sessions[0][0], 3)
+
     def test_forwarding(self):
         """ NAT44 forwarding test """
 
@@ -6936,6 +6950,8 @@ class TestNAT64(MethodHolder):
                 self.assertEqual(bibe.i_port, in_port)
                 self.assertEqual(bibe.o_port, out_port)
         self.assertEqual(static_bib_num, 1)
+        bibs = self.statistics.get_counter('/nat64/total-bibs')
+        self.assertEqual(bibs[0][0], 1)
 
         self.vapi.nat64_add_del_static_bib(in_addr,
                                            out_addr,
@@ -6949,6 +6965,8 @@ class TestNAT64(MethodHolder):
             if bibe.is_static:
                 static_bib_num += 1
         self.assertEqual(static_bib_num, 0)
+        bibs = self.statistics.get_counter('/nat64/total-bibs')
+        self.assertEqual(bibs[0][0], 0)
 
     def test_set_timeouts(self):
         """ Set NAT64 timeouts """
@@ -7031,6 +7049,11 @@ class TestNAT64(MethodHolder):
             '/err/nat64-out2in/good out2in packets processed')
         self.assertEqual(err - totaln, 3)
 
+        bibs = self.statistics.get_counter('/nat64/total-bibs')
+        self.assertEqual(bibs[0][0], 3)
+        sessions = self.statistics.get_counter('/nat64/total-sessions')
+        self.assertEqual(sessions[0][0], 3)
+
         # in2out
         pkts = self.create_stream_in_ip6(self.pg0, self.pg1)
         self.pg0.add_stream(pkts)
@@ -8094,6 +8117,11 @@ class TestNAT64(MethodHolder):
                                            vrf_id=prefix.vrf_id,
                                            is_add=0)
 
+        bibs = self.statistics.get_counter('/nat64/total-bibs')
+        self.assertEqual(bibs[0][0], 0)
+        sessions = self.statistics.get_counter('/nat64/total-sessions')
+        self.assertEqual(sessions[0][0], 0)
+
     def tearDown(self):
         super(TestNAT64, self).tearDown()
         if not self.vpp_dead:
@@ -8286,6 +8314,11 @@ class TestDSlite(MethodHolder):
         self.assertEqual(capture[IPv6].dst, self.pg1.remote_hosts[1].ip6)
         self.assertTrue(capture.haslayer(ICMPv6EchoReply))
 
+        b4s = self.statistics.get_counter('/dslite/total-b4s')
+        self.assertEqual(b4s[0][0], 2)
+        sessions = self.statistics.get_counter('/dslite/total-sessions')
+        self.assertEqual(sessions[0][0], 3)
+
     def tearDown(self):
         super(TestDSlite, self).tearDown()
         if not self.vpp_dead: